/Engine/Source/Runtime/Renderer/Public/ScreenPass.h
Describes a view rect contained within the extent of a texture. Used to derive texture coordinate transformations.
class FScreenPassTextureViewport
FIntPoint
Extent
The texture extent, in pixels; defines a super-set [0, 0]x(Extent, Extent).
FIntRect
Rect
The viewport rect, in pixels; defines a sub-set within [0, 0]x(Extent, Extent).